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EccIntPointMult
Scalar multiplication of a point on an elliptic curve.
Syntax:
nP := EccIntPointMult(K,E,n,P);
finite field |
K |
|
list |
E |
|
integer |
n |
|
list |
P |
|
list |
nP |
|
See also: EccPointsAdd, EccPointIsOnCurve, EccEncryptEccDecrypt, FF
Description:
Using the group law on an elliptic curve E over a finite field K
a point P=[x,y] on E is multiplied by the scalar n. E is
either given by a list of two or five elements of K or integers. If
the equation of E is y^2=x^3+a_4 x+a_6 the curve is represented
by [a_4,a_6], if the equation of E is
y^2+a_1 xy+a_3y=x^3+a_2x^2+a_4 x+a_6 then the representation is
[a_1,a_2,a_3,a_4,a_6]. Points on the curve are given by a pair of
elements of K or integers; the point at infinity is represented by
the empty list [\;].
Example:
kash> K := FF(11);
Finite field of size 11
kash> E := [0,0,0,1,6];
[ 0, 0, 0, 1, 6 ]
kash> EccIntPointMult(K,E,-1,[2,7]);
[ 2, 4 ]
kash> EccIntPointMult(K,E,5,[2,7]);
[ 3, 6 ]
kash> EccIntPointMult(K,E,12,[2,7]);
[ 2, 4 ]
kash> EccIntPointMult(K,E,13,[2,7]);
[ ]
kash> EccIntPointMult(K,E,14,[2,7]);
> [ 2, 7 ]
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